Technologies such as microelectronics, micromechanics and biotechnology have created a high demand for structuring and probing specimens within the nanometer scale. Micrometer and nanometer scale process control, inspection or structuring, is often done with charged particle beams. Examples of charged particle beam devices are electron microscopes, electron beam pattern generators, ion microscopes as well as ion beam pattern generators. Charged particle beams offer superior spatial resolution compared to photon beams, due to their short wave lengths.
Magnetic charged particle lenses have excitation coils which may be excited with high power. Thereby, the coil may heat up and a heat transfer from the coil to the pole pieces may occur. Even slight variations of the temperature of the pole pieces can lead to a thermal expansion. This thermal expansion may deteriorate the alignment of the charged particle beam column.
In light of the above, the coil might be surrounded by a thermally conductive housing, which is connected to a cooling pipe. However, homogeneous cooling system can be very complicated and areas of the thermally conductive housing, which are distant from the cooling pipe system, may show a temperature increase of up to 10° C.